The five-month search saw 125 teams from 22 different countries whittled down to a shortlist of seven potential designs for a landmark Pavilion, visitor centre with cafe, and surrounding public garden.

The competition brief required that the design be "inspired by, and appropriate to, the significance of its setting... compatible with the different existing and potential botanical, civic, cultural and commemorative uses of West Princes Street Gardens, which include a tranquil respite from the surrounding urban area."

The winning design is distinguished by its green-roofed, ‘butterfly’ Pavilion placed into the folds of the existing landscape.

The designers maintain even with an extensive new visitor centre just beneath Princes Street, the scheme increases the amount of green space relative to hard surfaces within the Gardens. It also introduces a new undulating promenade, transformed access from Princes Street, sculptural seating, and open views.

In the team’s words, the design is "human scale with moments of drama... activating four layers of meaning within the Gardens: botanical, civic, commemorative and cultural."

The jury praised the team’s concept design as "a beautiful and intensely appealing proposal that complemented, but did not compete with, the skyline of the City and the Castle."

Norman Springford, Competition Jury Chair, praised the way it “respects and enhances the historical context and backdrop of the Castle and the City, whilst creating new heritage and increasing the green space within the Gardens.”

Andy Neal, Trustee, The Ross Development Trust, echoed that sentiment adding “the design concept offers a creative energy and a series of unique elements which will all combine to create a new and contemporary landscape.”

Councillor Donald Wilson, Edinburgh’s Culture and Communities Convener, said: “The chosen design makes the most of the natural surroundings of Princes Street Gardens and focuses on connecting people to the city, the stage and the view of Edinburgh Castle.”

Malcolm Reading, Competition Director, described wHY’s design as “a landscape scheme that is really more like an energy-field: using animation and drama as well as open vistas, they transform the Gardens and create an experience that is much freer and organic.”

wHY, a collective with offices in New York and Los Angeles, was led by Founder and Creative Director Kulapat Yantrasast and Landscape Design Director Mark Thomann.

“wHY is built around an ecology of disciplines, the convergence of ideas, experience, nature and people,” said Yantrasast. “The Ross Pavilion and West Princes Street Gardens represent this convergence and this was the perfect ground to further our approach to design. To be selected from so many extraordinary thinkers is an honour. We felt a personal connection to the Gardens and believe our design embodies how important collaboration and people are to making a place remarkable.”

Mark Thomann, wHY’s Landscape Design Director, added: “This is a special opportunity for a special place, not just for Edinburgh but the world. The new Ross Pavilion and Gardens draw from the rich natural history, heritage and creative spirit of Scotland, embodying a model approach for integrating public architecture and urban space in a top global city. Our team looks forward to realising this vision with the Ross Development Trust and the people of Edinburgh.”